Abstract
The cement industry accounts for about 7% of all CO2 emissions caused by humans. Therefore, it is necessary to find another material in order to support sustainable material. An alternative way is replacing cement material with alternative material as fly ash. Fly ash as binder need to be added alkaline activator in the form of sodium silicate (Na2SiO3) or potassium silicate (K2SiO3) and sodium hydroxide (NaOH) or potassium hydroxide (KOH). The purpose of this research is to analyze the effect of activator liquid concentration on geopolymer mortar properties and to know the value of compressive strength. Molarity variation of NaOH are 8, 12, 14, and 16 M with ratio of Na2SiO3/NaOH = 1.0. Ratio of sand/fly ash = 2.75 and ratio of activator/fly ash = 0.8. The cube-shaped specimen 50 × 50 × 50 mm is cured by steam curing with a temperature of 60°C for 48 hours. The experimental result of fresh mortar reported that the molarity of NaOH affect the slump flow and setting time, higher of NaOH produces the smaller value of slump and the faster time of setting. The experimental of density results reported that the increase of specific gravity when the molarity of NaOH increased. The experimental results of the compressive strength are showed that the maximum compressive strength of geopolymer mortar 14 M is 10.06 MPa and the lowest compressive strength produced by geopolymer mortar 8 M is 3.95 MPa. Testing the compressive strength of geopolymer mortar 16 M produces compressive strength lower than 14 M geopolymer mortar is 9.16 MPa.
Highlights
Nowadays, construction world has been shown a fair progress with the development of materials technology
Fly ash is wasting material which is produced by the power plant and it can be used as an alternative replacement of cement material
Based on the previous research, the writer has conducted a manufacture of geopolymer mortar with alkaline activator sodium silicate (Na2SiO3) and sodium hydroxide (NaOH) as the catalyst of fly ash
Summary
Construction world has been shown a fair progress with the development of materials technology. One of the construction progress that had been developed was mortar. Mortar is the material used for building construction that is a mixture of fine aggregate, a binder, and water. The binder uses in mortar is cement. Fly ash should be added with an alkaline activator as a catalyst of fly ash. Alkaline activator that commonly used in geopolymerization is a combination of sodium silicate (Na2SiO3) or potassium silicate (K2SiO3) and sodium hydroxide (NaOH) or potassium hydroxide (KOH) [1]. The ratio of K2SiO3 to KOH in order to produce high strength of geopolymer mortar is in the range 0.8. Based on the previous research, the writer has conducted a manufacture of geopolymer mortar with alkaline activator sodium silicate (Na2SiO3) and sodium hydroxide (NaOH) as the catalyst of fly ash. This research is conducted to determine the properties of geopolymer mortar
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
